Call forwarding system



July 3, 1934. L KARDORFF 1,965,123 I CALL FORWARDING- S YSTEM Filed Nov13, 1931 Patented July 3, i934 UNITED- STATES CALL FORWARDING SYSTEMLon'Kardorfi, Hamburg, Germany, assignor to The American Self-SelectorCorp., a corporation of New York Application November 13, 1931, SerialNo. 574,914 in Germany July 10, 1931 19 Claims. (01. 179-18) Thisinvention relates to improvements in call forwarding systems, and hasfor an object the provision of means whereby subscribers who have two ormore automatic, or self-connecting telephone lines, such as is describedin co-pending application S. N. 550,338, iiled' July 13, 1931, maydirect calls, arriving at their telephones, further on to otherpredetermined subscribers.

Heretofore, it has not been possible for telephone subscribers to holdconversations over their telephone connections other than by the regularfixed connections.

By means of the system described and claimed herein, a telephonesubscriber is provided with a telephone system having furtherflexibility in that incoming messages may be automatically imparted toone or more predetermined telephones.

Referring to the drawing, Figure 1 shows one embodiment of the inventionin which an automatic selecting device is shown in circuit with twooflice telephone lines, all of the instrumentalities being showndiagrammatically; and

Figure 2 shows another embodiment of the invention in which means isdisclosed for automatically raising the switch-hook and therebyautomatically connecting the telephone assocated' with said switch-hookto the calling telephone.

To show the utility of such a system, a typical example of its use isherein given.- Assuming that a physician has a system of this characterwith two stations, each having a line connected to the central oifice,the telephones being of the so-called dial type, one of the lines may beassumed to be the line I, Figure l and the other line II in Figure l,the apparatus and operation of which will presently bedescribed. Nowassuming that the physician is invited to Mrs. Jones home to playbridge, the self selecting device shown in dotted lines in Figure 1 isset for Mrs. Jones telephone number by the physician before he leaveshome. He goes to Mrs. Jones home and is playing bridge. Now a partycalls the physician over line I in his ofiice. The calling current relayR closes the contacts 1' completing a local circuit including thebattery B, the electromagneticrelease Wof the self selecting device andthe magnet Z which inductively couples the lines I and IItogetherthrough the coupling member U. The self selecting device upon beingreleased calls Mrs. Jones telephone and when the latter is answered theparty originally calling the physician talks to him through line I, thecoupling device U, the line II and Mrs. Jones telephone, making itunnecessary for the physician to have someone in his oflice to answerthe telephone and transfer the calls to him.

Two oflice telephone lines, (1271 and abII (Figure 1) are so arrangedthat they may be inductively connected by means of a transmitting coilU. A calling current relay R is connected across. the line abI with acondenser in series. The line abII is inter-connected with theinterrupter con- 7 tacts nsa. and nsi of an automatic selecting'device,such as is described in the co-pendingAppln. Ser. No. 443,137, filedApr. 10, 1930 and applica tion Ser. No. 550,338, filed July 13, 1931,above referred to, in which the mechanism is provided with anelectromagnetic release for setting the mechanism into operation. 39

When the coil of the calling current relay R is energized by means of acall coming on the line abI, the contact 1 is closed and a circuit isset up which may be traced as follows: from the contact r via the sourceof electric current or battery B to the release magnet W of theselfselecting device to the magnet Z of the timeswitch and back to thecontact 1'.

When this circuit isenergized, after the operation of the callingcurrent relay R, the timeswitch leverh, attracted by the coil Z, isthereby pulled up in the direction shown by the arrow, thereby movingthe contact arms 1 and 2 to the left, as shown by arrow, and the contactarms 3 and 4, to the right, as is also shown by an arrow, therebyconnecting one winding of the transmitting coil to the lineabI andtheother winding of the transmitting coil U to the line abII.

At the same time, the release magnet W, of the self-selecting device,releases the mechanism therein and allows this device to operate, and bymeans of the same the desired station is selected.

As an alternative, a relay or similar. device may be substituted inplace of the time-switch having an electron winding Z and an armature hassociated therewith, for connecting the windings oi the transmittingcoil U to the lines abI and (dill. In this case the disconnecting of thetransmitting coil from the lines may be efiected by means of a sensitivereset coil forming an integral part of this relay, or by means of aseparate sensitive relay.

In the arrangement shown in Figure 2, two telephone stations, I and II,are shown, each having an ofiice line ab, which are adapted to beconnected by means of suitable mechanism provided for raising theswitch-hook of the telephone to be connected, and speaking connection isestablished and sound waves produced in the receiver and transmittedinto the microphone of the other telephone.

The operating coil R of a calling current relay having a condenser inseries therewith, is connected across the line ab of the telephonestation I. When the line abI is energized the coil R is thereby alsoenergized and the drop disc F is released and establishes contact withthe contact f, thereby establishing a circuit which may be traced asfollows: from the drop disc F to the contact 1, through the magnet coilZ of the timeswitch and via a source of current or battery 13 back tothe drop disc F.

As current passes through the magnet coil Z the contact arm is pulled tothe left in the direction of the arrow, closing the contact 2 andestablishing a circuit which may be traced as follows: from the contact,2 via the battery B to the solenoid coil H and back to the contact a.When the solenoid H is energized the switch-hook of telephone station IIis raised. The armature of the solenoid Z is pulled up, thereby raisingthe switch-hook of telephone station II. The action resulting from theraising of the solenoid armature will be presently described.

At the same time that the contact 2 was closed by the action of thetime-switch coil Z the hookswitch of telephone station I was raised.

A projection on the armature of the solenoid H, when the same is raised,closes the contacts h and establishes circuits which may be traced asfollows: from the contact 71. to the microphone or transmitter 111. andto the receiver or telephone t and via thebattery I) back to the contact71..

The transmitter m is placed adjacent to the receiver of the instrumentII and the telephone or receiver t is placed adjacent to the transmitterof station I, likewise, the transmitter m is placed adjacent to thereceiver of station I and the receiver t is placed adjacent to thetransmitter of station II, thereby speech impulses coming over the lineab to station I are transferred to the line ab of station II.

In the system described in Figure 1, station I may be inductivelycoupled to any line or lines selected by means of the automaticselector.

In the modification shown in Figure 2, impulses over the line ab ofstation I are transferred tothe line ab of station 11, by means ofmicrophones, or transmitters, and receivers co-operating with thereceivers and transmitters of the stations I. and II, respectively.

I claim-- 1. In a. call forwarding system a plurality of telephonestations and transmission lines therefor, an automatic selecting devicefor transmitting code signals to selecta predetermined station, acalling current relay associated with at least one of said stations, alocal circuit controlled by said relay, said circuit including means forinductively coupling two of said lines with each other and alsoincluding the control magnet of an automatic selecting device.

2. In a call forwarding system of the character described, a pluralityof telephone lines, an automatic selecting device for transmitting codesignals to select a predetermined station, a plurality of contact armsconnected to said lines, a second set of contact arms adapted to contactwith said flrstarms, a coupling coil having windings thereon connectedto said second set of arms, means including an electro-magnet foractuating the and a releasing magnet of an automatic selecting device.

3. In a call forwarding system a plurality of telephone stations andtransmission lines therefor, an automatic selecting device associatedwith any one of said stations and adapted to select any one of theplurality, a calling current relay associated with at least one of saidstations, a local circuit controlled by said relay, said circuitincluding means for inductively coupling two of said lines with eachother and also including the controlmagnet of the automatic selectingdevice.

4. In a call forwarding system of the character described, a pluralityof telephone lines, telephone stations associated with said lines, acalling current relay associated with one of said lines, a local circuitcontrolled by said relay including a timeswitch and a source of current,said time-switch being adapted to actuate a switching mechanism of oneof said stations and also adapted to control a second local circuitincluding said battery 5. In a call forwarding system for telephonesystems comprising a plurality of telephone subscriber stations, asubscribers station having an outgoing and incoming telephone line, anautomatic station selecting code transmitter at said subscribers stationand means responsive to an incoming call for automatically setting saidtransmitter into operation for transmitting a predetermined stationselecting code over said outgoing line.

6. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and-incoming telephone line, a normally non-operativeautomatic station selecting code transmitter at said subscribersstation, and means responsive to an incoming call for automaticallysetting said transmitter into operation for transmitting a predeterminedstation selecting code over said outgoing line.

7. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, a normally non-operativeautomatic station selecting code transmitter at said subscribersstation, and means responsive to an incoming call for automaticallysetting said transmitter into operation for transmitting a predeterminedstation selecting code over said outgoing line for simultane-' ouslyelectrically associating said incoming and outgoing lines whereby speechsignals received over one of said lines are repeated over the other ofsaid lines. 1

8. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, an automatic station selectingcode transmitter at said subscribers station, means responsive to anincoming call for automatically setting said transmitter into operationfor transmitting a predetermined' station selecting code over saidoutgoing line and means for simultaneously electrically connecting saidincoming and outgoing lines.'

9. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, an automatic station selectingcode transmitter at said subscribers station, means responsive to anincoming call for automatically setting said transmitter into operationfor transmitting a predetermined station selection code over saidoutgoing line, a telephone repeater intermediate said lines, normallynon-operative and means responsive to the incoming call for renderingsaid repeater operative to transmit signals received over one line tothe other.

10. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, a normally non-operativeautomatic station selecting code transmitter at said subscribers stationand means responsive to an incoming call for automatically setting saidtransmitter into operation for transmitting a predetermined stationselecting code over said outgoing line and for simultaneouslyelectrically associating saidincoming and outgoing lines.

11. In a call forwarding systemfor telephone systems comprisingaplura-lity of telephone subscriber stations, a subscribers stationhaving an outgoing and incoming telephone line, a normally non-operativeautomatic station selecting code transmitter atsaid subscribers stationand means responsive to an incoming call for automatically setting saidtransmitter into operation for trans mitting a predetermined stationselecting code over said outgoing line and for simultaneouslyelectrically associating said incoming and outgoing lines whereby speechsignals received over one of said lines are repeated over the other ofsaid lines.

12. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, a normally non-operativeautomatic station selecting code transmitter at said subscribers stationand means responsive to an incoming call for automatically settingsaidtransmitter into operation for transmitting a predetermined stationselecting code over said outgoing line and for simultaneouslyelectrically associating said incoming and outgoing lines whereby speechsignals received over one of said lines are repeated over the other ofsaid lines.

. '13. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, an automatic station selectingcode transmitter at said subscribers station, a local circuit at saidsubscribers station, a relay in the incoming line responsive totelephone calling signal frequency for controlling said circuit, aswitch for electrically associating the incoming and outgoing lines, arelay in said local circuit for operating said switch and meansresponsive to an incoming call for automatically setting saidtransmitter into operation for transmitting a predetermined sta-' tionselecting code over said outgoing line.

14. In a call forwarding system for telephone systems comprising aplurality of telephone subsponsive to telephone calling signal frequencyfor controlling said circuit, a switch for electrically associating theincoming and outgoing lines, a relay in said local circuit for operatingsaid switch and a second relay in said local circuit for starting saidautomatic station selecting code transmitter.

15. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a. subscribers stationhaving an outgoing and incoming telephone line, an automatic stationselecting code transmitter at said subscribers station, a local circuitat said subscribers station, a relay in the incoming line, responsive totelephone calling signal frequency for controlling said circuit, atelephone repeater, a switch for rendering said repeater operative totransmit speech signals from one of said lines to the other, a relay insaid local circuit for operating said switch and means responsive to anincoming call for automatically-setting said transmitter into operationfor transmitting a predetermined station selecting code over saidoutgoing line.

16. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, an automatic station selectingcode transmitter at said subscribers station, a local circuit at saidsubscribers station, a relay in the incoming line responsive totelephone calling signal frequency for controlling said circuit, atelephone repeater, a switch for rendering said repeater operative totransmit speech signals from one of said lines to the other, a relay insaid local circuit for operating said switch and a second relay in saidlocal circuit for starting said automatic station selecting codetransmitter.

17. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, a telephone repeaterintermediate said lines, normally non-operative, and means responsive tothe incoming calls for rendering said repeater operative to transmitspeech signals received over one line to the other and means forsimultaneouslyselecting a predetermined station over said outgoing line.

18. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, a telephone repeaterintermediate said lines, normally nonoperative, means responsive to theincoming calls for rendering said repeater operative to transmit speechsignals received over one line to the other and for simultaneouslyselecting a predetermined station over said outgoing line, said meanscomprising a local circuit at said subscribers station, a relay in theincoming line responsive to telephone calling signal frequency forcontrolling said circuit, a normally non-operative code transmitter fortransmitting a code to select a prede termined station, and a switch forelectrically associating the incoming and outgoing lines.

19. In a call forwarding system for telephone systems comprising aplurality of telephone subscriber stations, a subscribers station havingan outgoing and incoming telephone line, a telephone repeaterintermediate said lines, normally non-operative, means responsive to theincoming calls for rendering said repeater operative to transmit speechsignals received over one line to the other and for simultaneouslyselecting a predetermined station oversaid outgoing line, said meanscomprising a local circuit at said subscribers station, a relay in theincoming line re- 5- sponsive to telephone calling signal frequency forcontrolling said circuit, a normally non-operative

